Abstract: An updated account of 51 taxa of mosses of Rajasthan and Punjab plains is provided along with a note on delimitation of boundaries of this unique bryo-geographical zone. Family Pottiaceae is most dominant and diversified with 17 taxa under 11 genera while genus Fissidens (Fissidentaceae) has the maximum diversity with 7 species followed by Physcomitrium (Funariaceae) and Bryum (Bryaceae) with 6 species each.